when there is a problem with uploading data then info in Gui appears

frontend-js/.gitignore

+.idea/workspace.xml
 /dist/
 /coverage/
 /node_modules/

frontend-js/.idea/frontend-js.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/.tmp" />
+      <excludeFolder url="file://$MODULE_DIR$/temp" />
+      <excludeFolder url="file://$MODULE_DIR$/tmp" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file

frontend-js/.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/frontend-js.iml" filepath="$PROJECT_DIR$/.idea/frontend-js.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

frontend-js/.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

frontend-js/src/main/js/GuiConnector.js

@@ -4,6 +4,7 @@ var logger = require('./logger');
 
 var Functions = require('./Functions');
 var SecurityError = require('./SecurityError');
+var NetworkError = require('./NetworkError');
 
 /**
  * This static global object contains set of functions that returns/set data in
@@ -25,11 +26,11 @@ GuiConnector.yPos = 0;
  * List of GET params passed via url.
  */
 
-GuiConnector.init = function() {
+GuiConnector.init = function () {
   var self = this;
 
   if (!String.prototype.endsWith) {
-    String.prototype.endsWith = function(pattern) {
+    String.prototype.endsWith = function (pattern) {
       var d = this.length - pattern.length;
       return d >= 0 && this.lastIndexOf(pattern) === d;
     };
@@ -40,7 +41,7 @@ GuiConnector.init = function() {
     alert("This webpage works well with Chrome, Firefox and Safari.");
   }
   // bootstrap tab initialization
-  $("ul.nav-tabs a").click(function(e) {
+  $("ul.nav-tabs a").click(function (e) {
     e.preventDefault();
     $(this).tab('show');
   });
@@ -48,16 +49,17 @@ GuiConnector.init = function() {
   self.getParams = [];
 
   // find GuiConnector.getParams
-  window.location.search.replace(/\??(?:([^=]+)=([^&]*)&?)/g, function() {
+  window.location.search.replace(/\??(?:([^=]+)=([^&]*)&?)/g, function () {
     function decode(s) {
       return decodeURIComponent(s.split("+").join(" "));
     }
+
     GuiConnector.getParams[decode(arguments[1])] = decode(arguments[2]);
   });
 
   // forser browser to update mouse coordinates whenever mouse move
-  jQuery(document).ready(function() {
-    $(document).mousemove(function(e) {
+  jQuery(document).ready(function () {
+    $(document).mousemove(function (e) {
       GuiConnector.updateMouseCoordinates(e.pageX, e.pageY);
     });
   });
@@ -69,7 +71,7 @@ GuiConnector.init = function() {
       self.addWindowResizeEvent(window.onresize);
     }
 
-    window.onresize = function() {
+    window.onresize = function () {
       for (var i = 0; i < self._windowResizeEvents.length; i++) {
         self._windowResizeEvents[i]();
       }
@@ -77,18 +79,18 @@ GuiConnector.init = function() {
   }
 };
 
-GuiConnector.addWindowResizeEvent = function(handler) {
+GuiConnector.addWindowResizeEvent = function (handler) {
   this._windowResizeEvents.push(handler);
 };
 
 /**
  * Returns name of the file with LCSB logo.
- * 
+ *
  * @param bigLogo
  *          {@link Boolean} value determining if we want to have big logo or
  *          small one
  */
-GuiConnector.getLcsbLogoImg = function(bigLogo) {
+GuiConnector.getLcsbLogoImg = function (bigLogo) {
   if (bigLogo) {
     return 'lcsb_logo_mid.png';
   } else {
@@ -100,26 +102,26 @@ GuiConnector.getLcsbLogoImg = function(bigLogo) {
  * Returns name of the file with image that should be presented when we are
  * wainting for data to be loaded.
  */
-GuiConnector.getLoadingImg = function() {
+GuiConnector.getLoadingImg = function () {
   return "icons/ajax-loader.gif";
 };
 
 /**
  * Returns home directory for images in the application.
  */
-GuiConnector.getImgPrefix = function() {
+GuiConnector.getImgPrefix = function () {
   return "resources/images/";
 };
 
 /**
  * Updates coordinates of the mouse in the browser.
  */
-GuiConnector.updateMouseCoordinates = function(x, y) {
+GuiConnector.updateMouseCoordinates = function (x, y) {
   this.xPos = x;
   this.yPos = y;
 };
 
-GuiConnector.showProcessing = function(messageText) {
+GuiConnector.showProcessing = function (messageText) {
   var self = GuiConnector;
   if (self._processingDialog === undefined) {
     self._processingDialog = document.createElement("div");
@@ -127,11 +129,11 @@ GuiConnector.showProcessing = function(messageText) {
     self._processingDialog.appendChild(self._errorDialogContent);
     document.body.appendChild(self._processingDialog);
     $(self._processingDialog).dialog({
-      modal : true,
-      title : "PROCESSING",
-      width : "150px",
-      closeOnEscape : false,
-      open : function(event, ui) {
+      modal: true,
+      title: "PROCESSING",
+      width: "150px",
+      closeOnEscape: false,
+      open: function (event, ui) {
         $(".ui-dialog-titlebar-close", ui).hide();
       },
     });
@@ -140,8 +142,8 @@ GuiConnector.showProcessing = function(messageText) {
     messageText = "PROCESSING";
   }
   var messageImg = Functions.createElement({
-    type : "img",
-    src : 'resources/images/icons/ajax-loader.gif',
+    type: "img",
+    src: 'resources/images/icons/ajax-loader.gif',
   });
   self._errorDialogContent.innerHTML = "";
   self._errorDialogContent.style.textAlign = "center";
@@ -152,12 +154,12 @@ GuiConnector.showProcessing = function(messageText) {
   $(self._processingDialog).dialog("open");
 };
 
-GuiConnector.hideProcessing = function() {
+GuiConnector.hideProcessing = function () {
   var self = GuiConnector;
   $(self._processingDialog).dialog("close");
 };
 
-GuiConnector.alert = function(error) {
+GuiConnector.alert = function (error) {
   var self = GuiConnector;
   logger.error(error);
   if (self._errorDialog === undefined) {
@@ -166,18 +168,20 @@ GuiConnector.alert = function(error) {
     self._errorDialog.appendChild(self._errorDialogContent);
     document.body.appendChild(self._errorDialog);
     $(self._errorDialog).dialog({
-      classes : {
-        "ui-dialog" : "ui-state-error"
+      classes: {
+        "ui-dialog": "ui-state-error"
       },
-      modal : true,
-      title : "ERROR"
+      modal: true,
+      title: "ERROR"
     }).siblings('.ui-dialog-titlebar').css("background", "red");
   }
   var message = error;
   if (message instanceof SecurityError) {
-    message = error.message + "<p>Please <a href=\"login.xhtml\">login</a> to access this resuorce</p>";
+    message = error.message + "<p>Please <a href=\"login.xhtml\">login</a> to access this resource</p>";
+  } else if (message instanceof NetworkError && (error.message === "XHR error" || error.message === "Failed to fetch")) {
+    message = "File to big.<br>Please reduce file size or contact administrators.";
   } else if (message instanceof Error) {
-    message = "Unexpected error occured:<p>" + error.message + "</p>";
+    message = "Unexpected error occurred:<p>" + error.message + "</p>";
   }
   self._errorDialogContent.innerHTML = message;
   $(self._errorDialog).dialog("open");

frontend-js/src/main/js/ServerConnector.js

@@ -155,7 +155,7 @@ ServerConnector.sendPostRequest = function (url, params) {
       form: params
     }, function (error, response, body) {
       if (error) {
-        reject(new NetworkError(error, {
+        reject(new NetworkError(error.message, {
           content: body,
           url: url
         }));

frontend-js/src/main/js/gui/leftPanel/OverlayPanel.js

@@ -449,7 +449,7 @@ OverlayPanel.prototype.openAddOverlayDialog = function () {
         }
       }
       if (fileContent === null) {
-        GuiConnector.alert("Neither file was selected nor data was enterd");
+        GuiConnector.alert("Neither file was selected nor data was entered");
       } else {
         var data = {
           name: nameInput.value,
@@ -466,15 +466,11 @@ OverlayPanel.prototype.openAddOverlayDialog = function () {
           $(dialog).dialog("close");
         }, function (error) {
           GuiConnector.hideProcessing();
-          if (error instanceof NetworkError) {
-            if (error.statusCode === HttpStatus.BAD_REQUEST) {
-              var errorMessage = JSON.parse(error.content);
-              GuiConnector.alert("Problematic input: <br/>" + errorMessage.reason);
-            } else {
-              throw error;
-            }
+          if (error instanceof NetworkError && error.statusCode === HttpStatus.BAD_REQUEST) {
+            var errorMessage = JSON.parse(error.content);
+            GuiConnector.alert("Problematic input: <br/>" + errorMessage.reason);
           } else {
-            throw error;
+            GuiConnector.alert(error);
           }
         });
       }